Retromaster’s Electronics Projects

…related to old computers and other assorted stuff…

TFE

TFE is an SD/MMC floppy drive emulator for old computers that I have developed. It connects to the floppy drive port of the host computer and behaves like a real floppy drive, except that the data comes from the SD/MMC card instead of real media. It is quite similar to existing projects such as HxC Standalone or SDiskEmul.

Video

The video below shows the previous version (Revision B) of TFE in operation. Revision B has a different, double-sided PCB layout, a DB15 connector, and no buzzer. Otherwise, it is functionally identical to Revision C.

Vodpod videos no longer available.

Motivation

We love old computers but floppies can be a nuisance. They are error-prone, they take up a lot of space, and nowadays they are becoming more and more difficult to get. TFE was created to enable usage of SD Card media instead of floppy disks to alleviate these problems to a certain extent.

Features

  • Read access for AMIGA, ATARI ST and CPC computers is supported. Standard IDC 34-pin floppy connector. Other computers with WD1772 or UPD765 controllers may work, but have not been tested.
  • Atmega32-based, low parts count, single-sided PCB, easy to build (no SMD).
  • Uses own disk image format for emulation. Standard Floppy disk images (ADF, DSK, etc.) are converted to the TFE format by using converter utilities on the PC.
  • Can co-exist with other floppy drives on the same bus.
  • FAT32 (defragmented) and long file name support for the SD Card. Firmware updates can be made through SD Card.
  • Composite video output and joystick port for the user interface, and buzzer for emulating head stepping ticks.

Known Problems and Limitations

  • Write access is not supported.
  • Video output is disabled when floppy emulation is active.
  • SD Card FAT32 file system must be defragmented, and subdirectories are not supported. SD Card-related limitations may be removed in a future firmware release.

How to use

TFE is connected to the host computer using the standard 34-pin floppy connector. If necessary, the SEL line must be adjusted using the jumpers on TFE board to determine the drive ID. TFE composite video output may be connected to a monitor or a TV. TFE must be powered using the connector on board (9V to 12V DC, positive inside). Convert the images you would like to use to .TFE files using the appropriate conversion utility, and copy the .TFE files to a FAT32-formatted SD card.

To be able to switch between host computer video output and TFE output, a monitor with multiple inputs, or a cheap SCART switch can be used. To workaround the problem of defragmented filesystem, you can “quick format” the SD card right before copying the files to it.

Compatibility

  • Amiga .ADF: Very good, I have never encountered any problems with any of the images I’ve tested.
  • Amiga .IPF: Not supported.
  • Amstrad CPC .DSK: With standard images, compatibility is very good . With copy-protected images, compatibility is somewhat low, but improvements are being made.
  • Atari ST .MSA/.ST: Very good, I have never encountered any problems with any of the images I’ve tested.

Any existing compatibility issues may be addressed by future updates to conversion utilities.

Downloads

To be available soon.

Technical Info

Detailed technical information including schematics can be found here (not complete yet).

Disclaimer

This information here is provided AS IS without any express or implied warranties. While every effort has been taken to ensure the accuracy of the information contained in this text, the author assumes no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. I will not be held responsible for any damages or costs which might occur as a result of anything related to TFE. You are not allowed to use information contained in these pages for commercial purposes without my written authorization.

25 Responses to “TFE”

  1. TFM said

    Hi,

    The TFE project seems to be a wonderfull alternative to 3″ disc drives on the Amstrad CPC! What a fantastic project!

    Now I got some questions:

    – Can I use the TFE also as drives C or D (means DS2 or DS3) on the CPC?

    – Is it possible to perform a test with a CPC6128 and FutureOS? Since I’m for some longer time in USA and my CPCs are in Europe, I can’t do it.

    – How can the TFCs be ordered?

    Thank you for your help. And keep on creating such wonderfull projects!

    Bye,
    TFM of FutureSoft

  2. retromaster said

    Hi,

    To the best of my knowledge, on stock CPC6128s it’s not possible to use more than 2 floppy drives. However, I have read that it is possible to use 4 drives by means of a hardware modification and software that knows how to make use of it.

    If the appropriate hardware mods were applied, TFE would work properly as any one of the four drives. Appropriate cabling would be required though. For example, the external floppy connector on the CPC6128 has only one SEL line available (only the one for the B drive). Using that connector, it would not even be possible to use TFE as the A drive, if it were not for the “Invert Select” feature that I’ve recently added. I’ll update the page to give more information on this later.

    I’d like to test with FutureOS but I do not have a machine with FutureOS roms at the moment. Hopefully later when I have some more time…

    The TFE is not for sale at the moment, due to lack of time on my part, however this situation can change in the near future.

    Thanks for your kind words,
    RM

  3. TFM said

    Hi,

    Yes right, with a little hardware modification you can use 4 instead of 2 drives on the CPC. This makes sense f.e. if you connect two floppys of 0.7 MB Vortex format to copy a disc directly. Some software support it.

    Now I can only hope that TFE will be available soon for the public. I’m really looking forward to use it with my real CPC.

    Bye,
    TFM

  4. Tolkin said

    Hy, would love to see a public release for this really nice peripherial.
    Many of the CPC Users will be very happy for this item.
    Is there a chance that a batch of devices will be sold in the future?
    Keep up the good work!😉
    Bye
    Tolkin

  5. Tolkin said

    Or maybe would there be a selfmade kit. For soldering at home…

  6. retromaster said

    I am considering both fully-assembled and kit versions but as I have previously mentioned I do not have enough time ATM to dedicate to this. Hopefully in the near future.

  7. Fernando said

    Hi!

    Very interesting. I wonder: how difficult would it be for this project to be extended to support emulation of a 1.44MB 3.5″ HD diskette drive?

    Best
    FC

  8. retromaster said

    Hi, I considered HD support at some point but I remember I dropped it for some reason, although I do not remember exactly why. The whole setup would need to work at double the current speed, but if the SD card read can keep up, it should not be a problem, really.

  9. Pani said

    Would this also allow one to replace a floppy drive on for example, a cnc cutting machine, and emulate a floppy drive, and allow one to use a usb key instead?

    If it would, I would buy one of anyone who can make this for me – email me at info@seabase.eu

  10. retromaster said

    It could replace floppy drive on a CNC machine, but it won’t let you use a USB key. Only SD cards are supported. Also, please be aware that the user interface requires a monitor (TV) that can display composite video, but you could make it work without it, in a “blind” way. ATM, there is nobody but me who can build this for you, as I haven’t released source code or binaries. I will announce in these pages when (if) the device becomes available for purchase.

  11. shinmai said

    If at any point you decide to sell this fully-assembled, I would be willing to part with considerable amounts of money to get one. I’m dying for something like this for my Atari ST, which is pretty much useless now, that it’s floppy drive and hard drive both died.

  12. retromaster said

    Shinmai, please see the my latest blog post on this topic.

  13. Moe said

    Hi,

    Could you post some datasheets of your design?

    HxC Standalone is doing so for those that are intrested:

    Thanks,
    Moe

  14. retromaster said

    The schematics have been available for quite some time in the Technical Info section .

  15. Richard said

    Hello Dr. Retromaster!

    I am Richard Gabor Tarjan, the maintaner of the world wide famous ‘ZX Spectrum in the 21st Century?’ site.
    It is here:
    http://tarjan.uw.hu/zxclones_en.htm

    I have a question. If your device is supporting the Amstrad CPC range, it is possible to work fine with the ZX Spectrum +3? And its derivates, as the +2A/B? It has the same floppy system as CPCs.
    And furter more. The HcX emulator also supports the Russian originated disk formats (trd, scl etc.). It is possible to expand your SD Card emulator to do that? Because would be nice to play the newer, fantastic Russian games on a real Spectrum, rather than an emulator.

    If the answer is ‘yes’ for at least for the first question, your SD Card emulator will added to my homepage at the next update (I have 300-400 visitors/week for the hardware part).

    Waiting your response: Richard

  16. retromaster said

    Hello Richard,

    I think TFE would work with a Spectrum +3 (and probably the +2). The reason I’ve never mentioned the Spectrum compatibility is because it was never tested, mainly because I do not own a Spectrum +3 (although I would like to🙂 ). In the worst case, a firmware fix may be required, but most likely even that won’t be necessary.

    For the disk format support question, I think this is a matter of writing the necessary conversion utilities. TFE can only directly load raw MFM files, and for all supported disk formats (such as .ADF, .ST, .DSK) I’ve written the utility programs necessary for this conversion. If similar utilities are written for the formats you mentioned, I think they would work.

    By the way, you’ve done a great job on your website, congratulations.
    -RM

  17. Richard said

    Hello Dr. Retromaster,

    It is me agian. In this weekend I would like to update my wensite (on my laptop first;) with the TFE ‘as a poosibly ZX Spectrum peripheral’. For relizing this nice quest, I would like to ask you something, if you don’t mind:

    1. Please describe me, what is the difference beetwen ‘TFE’ AND ‘TFE+’.
    2. Can you send me photos about TFE and TFE+? 1024*768 JPEG both solder and compomnt sides of TFE and TFE+. I need them beacuse I wanted pure photos without CPC, ST or Amiga.
    3. Can you usnsubsribe me? Coz I was subscribed accidentaly.

    Waiting you letter:

    Richard (Hungary)

  18. retromaster said

    Hi Richard,

    1. The difference between TFE and TFE+ is that the TFE+ has a better user interface. It is designed to accept user input from the host system keyboard and to overlay its video output on top of the host system video output. So, no separate joystick to control the floppy emulator UI or separate switching for video output, etc. Much simpler, a lot less cabling, self-contained…

    Of course, this makes the TFE+ more system-dependent, since every type of home computer has its own keyboard interface. So, the only existing TFE+ prototype is specific to the Amiga.

    I also originally intended for the TFE+ to support write emulation, but it turned out that it was not possible to do reliably with the TFE+ hardware design. So, I have dropped the TFE+, now I am working on the UFE, which takes all the good properties of TFE+ and it will have fast on-board image to MFM encoding and write support, etc. It will also be system independent, because the keyboard interface will be implemented on a daughterboard. I have made a lot of progress, you can read about it in the main blog.

    2. There are photos of TFE alone on this webpage. Do you need higher resolution photos? Also, do you still want the photos of TFE+? (since it does not work for the Spectrum).

    3. No problem.

    Glad to hear from you again,
    -RM

  19. David said

    Hi, I’ve been looking into the HxC for not only reading floppies, but also MFM Hard disk drives.

    Is this something this new UFE you mention?

    If it’s possible to add support I’d be interested.

    David.

  20. retromaster said

    UFE, TFE and HxC are completely independent projects. UFE may be considered the successor of TFE. You can get more information on UFE here.

    I have no plans to add MFM hard disk support to both projects at the moment.

  21. Dux said

    If you could produce HD floppy emulator in FDD form factor to directly replace the FDD unit, millions of old musical keyboard owner will buy it. There’s a huge captive market waiting!

  22. Mard said

    Download will be available soon?🙂

  23. retromaster said

    Download will be available soon?

    Probably yes, since I’ve developed the UFE now. But I need to find the time to wrap everything up…

  24. khan said

    Does this require software/driver to connect with existing hardware.

  25. retromaster said

    @khan: No.

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